Swiss Side reacts to the UCI wheel depth ruling and launches the HADRON³ Ultimate 650 wheelset

Swiss Side has today launched a new 65mm deep wheelset that complies with the UCI rules on maximum wheel depth, which will come into effect on January 1st, 2026.

The new wheelset is the HADRON³ Ultimate 650, which adheres to the UCI equipment rules regarding rim depth, which were announced in June this year.

At the time, the UCI ruling, like others this year, such as the controversial minimum handlebar width and gear limitation rules, both supposedly measures to decrease race speeds and thus increase safety, was met with resistance, and Swiss Side CEO Jean-Paul Ballard published an open letter to the UCI at the time of the ruling protesting and 'scientifically challenging' the decision. The brand argued that rim shape, and not just depth, dictates stability and safety.

The UCI ruling must have caused extra frustration for the Swiss brand, who supply wheels to the Decathlon AG2R La Mondial team, coming just two weeks before the company was set to launch its 68mm HADRON³ Ultimate ‘680’ wheel set.

This new road bike wheelset has a 3mm shallower rim than the UCI illegal 680 wheelset, which can, in fact, still be used for non-UCI-sanctioned events and triathlons. The wheel features the same 22mm internal rim width, but Swiss Side claims it was developed to enhance riding stability. With a claimed -12% reduction in crosswind sensitivity, a weight decrease of 33 grams and a +0.5W aerodynamic drag increase.

The wheels will launch with an MSRP of €2,699, as well as an initial online price: €2,159. Alongside the 65mm option, Swiss Side offers the HADRON³ Ultimate in 38,55,68 and 85mm options, as well as a disc wheel for TT and triathlon.

Swiss Side says the Hadron Ultimate range achieves 'class-leading aero efficiency' and does indeed appear to focus on aerodynamics and rider stability for a more aerodynamic total system.

Swiss Side provides a lot of information on its aero work and testing; the brand's website contains a lot of interesting reading. CEO Ballard comes from a Formula 1 background and has transferred his aero concepts to the bike world. An example would be the Swiss Side / DT Swiss / Continental Aero 111 front wheel-specific tyres.

Swiss Side claims a lower overall base drag aids its wheels. It defines this as the 'maximum drag level of the wheel with primarily frontal airflow' (between +/-5° yaw, or wind direction). Claiming with this, thanks to a V-Shape rim profile, the rider saves in all wind conditions.

Handling for safety and aero appears to be a priority, and Swiss Side explains that a more stable wheel will lead to fewer corrections from a rider in windy conditions, which can create drag, whilst allowing them to remain in an aerodynamic position.

The brand claims all HADRON³ wheels have at least the same steering moment for each rim depth, regardless of depth increases. In short, it says rim shape determines stability, and with the right profile, stability and safety aren't impacted. This is the crux of the Swiss Side argument regarding the depth ruling.

The rims are hooked, which the brand says gives maximum tyre size and pressure compatibility. The wheels also use smaller-sized DT Swiss / Swiss Side aero hubs, which provide another claimed aerodynamic advantage. Spoke count on the front wheel was also reduced from 24 to 20 spokes on Ultimate wheels for less weight and rotational drag.

This new wheelset appears to show that the deepest wheelset possible for road racing is a requirement for Swiss Side. The launch of the 650 wheels means the brand can offer the deepest possible wheelset for racers, whilst meeting the UCI's maximum rim depth criteria.